1. Field of the Invention
The present invention relates to a memory cell array.
2. Description of Related Art
Currently, further miniaturization of an electrical element is desired as a device is getting smaller and its density is increasing. As an example of such case, there has been known a switching element which can perform a switching operation by applying a voltage between two conductive bodies facing each other across a microscopic space (nanogap).
Specifically, for example, there has been developed a switching element which is composed of stable material of oxide silicon and gold, manufactured by a simple manufacturing method of oblique vapor deposition, and capable of repeating switching operation stably (for example, see Japanese Patent Application Laid-Open No. 2005-79335).
There has also been developed a switching element which can be arranged at a high density and its integration becomes easy by aligning two conductive bodies facing each other across a nanogap in vertical direction (for example, see Japanese Patent Application Laid-Open No. 2008-243986).
In order to apply such switching element (hereinafter referred to as “nanogap element”) including the nanogap to a high-density memory, it is necessary to relate a “low resistance state” and “high resistance state” which corresponds to “ON” and “OFF” respectively to “zero (0)” and “one (1)” of the memory, and arranging nanogap elements in an array to construct a memory cell array.
Conventionally, as a memory cell array, there has been known a Dynamic Random Access Memory (DRAM) memory cell array (for example, see Japanese Patent Application Laid-Open No. 2000-269358).
A memory cell provided in the DRAM memory cell array includes, for example, a memory cell containing a metal-oxide semiconductor (MOS) transistor and a capacitor as shown in FIG. 9.
However, since the memory cell included in the DRAM memory cell array uses the capacitor as the memory element, there is a problem that it is difficult to further miniaturize the memory cell array or to increase its density.